A conventional machining apparatus 8 is illustrated in FIG. 10. The machining apparatus is for machining rubber/plastic plates to have desired figures and patterns thereon. A rubber/plastic plate 82 is placed on a second mold blade 81 of a second mold stage 80 and a rubber/plastic plate 92 is placed on a third mold blade 91 of a third mold stage 90. A hydraulic cylinder apparatus 110 placed below the third mold stage 80. The hydraulic cylinder apparatus 110 contains a stretchable rod 111 connected to the third mold stage 80. The second mold stage 80 is raised by the stretchable rod 111 to press against the bottom of the third stage 90. Then the third mold stage 90 is pushed by the second mold stage 80 to press against the bottom of the first mold stage 100, which is fixed at the machining apparatus. When the rubber/plastic plate 82, 92 are pressed, the mold stages 80, 90, 100 are heated to soften the rubber/plastic plate 82, 92. Thereby, the mold blades 81, 91 cut and form desired patterns on the rubber/plastic plate 82, 92.
The sizes of the mold blades 81, 91 need to be exchanged to fit different rubber/plastic plates. Therefore the stretching distance of the stretchable rod need to be adjusted depends on different rubber/plastic plates. The stretching distance of the stretchable rod 11 is controller by a controller of a hydraulic cylinder system. However, the volume of the oil within the hydraulic cylinder apparatus 110 varies when the surrounding temperature varies. Accordingly the stretching distance is difficult to be precisely controlled. When the actual stretching distance is longer than desired stretching distance, the mold blades 81, 91 will be over-pressed and therefore damaged. To avoid damages of the mold blades, users will usually set the stretching distance a little shorter than desired stretching distance. The patterns still can be formed by the mold blade 81, 91 but the edges of the mold blades 81, 91 cannot cut through the rubber/plastic plates 82,92 to desired shapes. Therefore another processing machine is needed to cut the rubber/plastic plates 82,92 to desired shapes. The cost of the manufacture is increased because of the additional machine and the qualities of the products are not good because the manufacturing process cannot be completed within one machine.
Therefore a machining apparatus that can avoid damages of the mold blades and also can precisely cut the raw material such as rubber or plastic plates to desired shape and have desired patterns thereon is needed.